\section{Conclusion}
\label{con}
In this paper, we propose a new variant of TCP for clouds named
Adaptive TCP. Our work is motivated by the fact that TCP's fairness
does not differentiate among delay-sensitivity of applications, while
existing solutions require
draconian changes to applications, infrastructures and the service
models. Based on measurements that delay-sensitive applications
typically use short flows, and that the flows often co-exist with
large flows, our scheme is designed to ``steal''
bandwidth from large flows over time and reallocate to small 
ones, and to ``compensate'' large flows by more transfer time. 
We achieve this via simple adjustment of TCP's additive increase
parameter as a function of data sent, requiring minimal changes to the
cloud software infrastructure, leaving applications and hardware
unmodified. Simulations based on real data center traces show that
ATCP reduces small flow completion time significantly without 
influencing large flows. As a result the performance of time-sensitive 
applications is improved.

